U.S. Department of Commerce Economics and Statistics Administration U.S. CENSUS BUREAU 

# Age and Sex Composition: 2010 2010 Census Briefs

By Lindsay M. Howden and Julie A. Meyer C2010BR-03 

### Issued May 2011



### INTRODUCTION Focusing on a population’s age and sex composition is one of the most basic ways to understand population change over time. Since Census 2000, the population has continued to grow older, with many states reaching a median age over 40 years. At the same time, increases in the num ber of men at older ages are apparent. Understanding a population’s age and sex composition yields insights into changing phenomena and highlights future social and economic challenges. This report describes the age and sex composition of the United States in 2010. It is part of a series that provides an overview of the population and housing data collected from the 2010 Census. It highlights analysis of age and sex at the national level, as well as for regions, states, and counties and for places with populations of 100,000 or more. A com parison with Census 2000 data is also provided, showing the changes in age and sex composition that have taken place over the last 10 years. This report also provides information about how age and sex data were col lected in the 2010 Census. The data for this report are based on the **2010 Census Summary File 1**  , which is among the first 2010 Census data products to be released. 1 

### SEX AND AGE QUESTIONS Data on the sex and age composition of the United States and your community are derived from the 2010 Census questions on sex, age, and date of birth (Figure 1). The sex question remains unchanged from the previous census. Information on the sex of individuals is one of the few items obtained in the original 1790 Census and in every census since. As with sex, information on age has been collected since 1790. The 2010 Census age data were derived from a two-part question. The first part asked for the age of the person, and the second part asked for the date of birth. The question is 1 The **2010 Census Summary File 1** (SF1) con tains data on age, sex, race, Hispanic origin, group quarters, relationship, tenure, and households at a variety of geographic levels down to the block level. For a detailed schedule of 2010 Census products and release dates, visit < www.census.gov/population /www/cen2010/glance/index.html >. 

### Figure 1. 

### Reproduction of the Questions on Sex, Age, and Date of Birth From the 2010 Censu s

Sour ce: U.S. Census Bureau, 2010 Census questionnair e.

### 2 U.S. Census Bureau 

### designed in two parts in order to maximize both the accuracy and the number of people responding to this item. The age question itself is unchanged since Census 2000, however, an instruction was added to guide respondents to report the ages of babies as 0 years old if they were less than 1 year old. In previous censuses, research ers found that respondents often reported their babies’ ages in terms of days, weeks, or months, rather than in terms of years. This instruc tion was added to reduce reporting problems for babies. 

### AGE AND SEX COMPOSITION According to the 2010 Census, the population of the United States on April 1, 2010, was 308.7 million people, representing a 9.7 per cent increase in population since 2000, when the population was 281.4 million (Table 1). Growth was slower than the 13.2 percent increase experienced during the previous decade, but similar to the growth between 1980 and 1990 (9.8 percent). Of the 2010 Census population, 157.0 million were female (50.8 percent) while 151.8 million were male (49.2 percent). Between 2000 and 2010, the male population grew at a slightly faster rate (9.9 percent) than the female population (9.5 percent). The population grew at a faster rate in the older ages than in the younger ages. The data presented in Table 1 also include the distribution of the population for selected age cat egories. In the 2010 Census, the number of people under age 18 was 74.2 million (24.0 percent of the total population). The younger working-age population, ages 18 to 44, represented 112.8 million persons (36.5 percent). The older working-age population, ages 45 to 64, made up 81.5 million persons (26.4 percent). Finally, the 65 and over population was 40.3 million persons (13.0 percent). Between 2000 and 2010, the popu lation under the age of 18 grew at a rate of 2.6 percent. The growth rate was even slower for those aged 18 to 44 (0.6 percent). This contrasts with the substantially faster growth rates seen at older ages. The population aged 45 to 64 grew at a rate of 31.5 percent. The large growth in this age group is primarily due to the aging of the Baby Boom population. 2 

### Finally, the population aged 65 and over also grew at a faster rate (15.1 percent) than the population under age 45. Another important tool for analyz ing the age and sex composition of the population is the age-sex pyramid (Figure 2). The age-sex pyramid shows the number of males (on the left) and number of females (on the right) by single years of age. The 2000 and 2010 pyramids are superimposed to make it easy to study the popu lation at each point in time and to assess change. The shape of the pyramid can give important information about the population’s

2 The Baby Boom includes people born from mid-1946 to 1964. The Baby Boom is distinguished by a dramatic increase in birth rates following World War II and comprises one of the largest generations in U.S. history. For more information, see Howard Hogan, Deborah Perez, and William Bell, **Who (Really) Are the First Baby Boomers?**  Joint Statistical Meetings Proceedings, Social Statistics Section, Alexandria, VA: American Statistical Association, 2008, pp. 1009–16. 

### Table 1. 

### Population by Sex and Selected Age Groups: 2000 and 2010 (For information on confidentiality protection, nonsampling error, and definitions, see **www.census.gov/prod/cen2010/doc/sf1.pdf** ) Sex and selected age groups 2000 2010 Change, 2000 to 2010 Number Percent Number Percent Number Percent **Total population . . . . . . . . . . . . .**  **281,421,906 100**  **. 0**  **308,745,538 100**  **. 0**  **27,323,632 9**  **. 7**  **SEX** Male . . . . . . . . . . . . . . . . . . . . . . . . . . . 138,053,563 49 . 1 151,781,326 49 . 2 13,727,763 9 . 9 Female . . . . . . . . . . . . . . . . . . . . . . . . . 143,368,343 50 . 9 156,964,212 50 . 8 13,595,869 9 . 5 **SELECTED AGE GROUPS** Under 18 years . . . . . . . . . . . . . . . . . . 72,293,812 25 . 7 74,181,467 24 . 0 1,887,655 2 . 6

Under 5 years . . . . . . . . . . . . . . . . . 19,175,798 6 . 8 20,201,362 6 . 5 1,025,564 5 . 3 5 to 17 years . . . . . . . . . . . . . . . . . . 53,118,014 18 . 9 53,980,105 17 . 5 862,091 1 . 6 18 to 44 years . . . . . . . . . . . . . . . . . . . 112,183,705 39 . 9 112,806,642 36 . 5 622,937 0 . 6

18 to 24 years . . . . . . . . . . . . . . . . . 27,143,454 9 . 6 30,672,088 9 . 9 3,528,634 13 . 0 25 to 44 years . . . . . . . . . . . . . . . . . 85,040,251 30 . 2 82,134,554 26 . 6 –2,905,697 –3 . 4 45 to 64 years . . . . . . . . . . . . . . . . . . . 61,952,636 22 . 0 81,489,445 26 . 4 19,536,809 31 . 5 65 years and over . . . . . . . . . . . . . . . . 34,991,753 12 . 4 40,267,984 13 . 0 5,276,231 15 . 1 16 years and over . . . . . . . . . . . . . . . . 217,149,127 77 . 2 243,275,505 78 . 8 26,126,378 12 . 0 18 years and over . . . . . . . . . . . . . . . . 209,128,094 74 . 3 234,564,071 76 . 0 25,435,977 12 . 2 21 years and over . . . . . . . . . . . . . . . . 196,899,193 70 . 0 220,958,853 71 . 6 24,059,660 12 . 2 62 years and over . . . . . . . . . . . . . . . . 41,256,029 14 . 7 49,972,181 16 . 2 8,716,152 21 . 1 Sources: U . S . Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1 .U.S. Census Bureau 

### 3composition. The 2010 Census agesex pyramid is typical of developed countries, showing a broad base with a middle section of nearly the same dimension and then gradually tapering off at the oldest ages to a point at the top. Between 2000 and 2010, the population pyramid has become more rectangular in shape. The Baby Boom population in 2010 is evident in the pyramid as a bulge at ages 46 to 64. Consistent with this trend, the age group 60 to 64 was the five-year age group with the largest percent increase (55.6 percent) followed by the 55 to 59 age group (46.0 percent) (Table 2). The five-year age group with the largest percent decrease was the population aged 35 to 39 (11.1 percent decrease). The lopsided point at the top of the pyramid indicates differences in the number of males and females at older ages. This is a result of differences in mortality for men and women, where women tend to live longer than men. These mortality differences between men Figure 2. 

### Population by Age and Sex: 2000 and 2010

2010 (For information on confidentiality protection, nonsampling er ro r, and definitions, see **www.census.gov/prod /cen2010/doc/sf1.pdf**  )

Male Female Age 2000

Sour ces: U.S. Census Bur eau, **Census 2000 Summary File 1**  and **2010 Census Summary File 1**  . Millions 0 1 .0 2. 0 3 .0 3.0 2.0 1.0 0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100+

### 4 U.S. Census Bureau 

### and women also impact another important indicator of population composition, the sex ratio. Faster growth in the male population led to increased sex ratios. The sex ratio is a common mea sure used to describe the balance between males and females in the population. It is defined as the number of males per 100 females. A sex ratio of exactly 100 would indicate an equal number of males and females, with a sex ratio under 100 indicating a greater number of females. The sex ratio at birth in the United States has been around 105 males for every 100 females, however, since mortality at every age is generally higher for males, the sex ratio naturally declines with age. This tendency progresses through ages 85 and above where there are considerably more surviv ing women. These trends result in more males at younger ages and more females at older ages. Sex ratios can vary from these pat terns for many reasons such as the impact of international or domes tic migration on a population or features of the geographic location (for example, the existence of col lege student housing or military facilities). In 2010, there were 96.7 males per 100 females, an increase from 2000 when the sex ratio was 96.3 males per 100 females, resulting from a greater increase of males than females over the decade. Looking at five-year age groups reveals a noteworthy increase in the sex ratios for the population aged 60 and older between 2000 and 2010 (Figure 3). This change results from a greater increase in the male population relative to the female population for these age groups. Males aged 60 to 74 increased by 35.2 percent while their female counterparts increased by 29.2 percent (Table 2). A narrowing of the mortality gap between men and women at older ages in part accounts for this difference. Population aging led to an increased median age. Changes in the structure of the population also impact another measure of population composi tion, median age. The median age is the age at the midpoint of the population. Half of the population is older than the median age and Table 2. 

### Population by Age and Sex: 2000 and 2010 (For information on confidentiality protection, nonsampling error, and definitions, see **www.census.gov/prod/cen2010/doc/sf1.pdf** ) Age 2000 2010 Percent change, 2000 to 2010 Both sexes Male Female Both sexes Male Female Both sexes Male Female **All ages . . . . . . . .**  **281,421,906 138,053,563**  **143,368,343 308,745,538**  **151,781,326 156,964,212**  **9 .**  **7 9**  **. 9**  **9 .**  **5** Under 5 years . . . . . . . 5 to 9 years . . . . . . . . . 10 to 14 years . . . . . . . 15 to 19 years . . . . . . . 20 to 24 years . . . . . . . 25 to 29 years . . . . . . . 30 to 34 years . . . . . . . 35 to 39 years . . . . . . . 40 to 44 years . . . . . . . 45 to 49 years . . . . . . . 50 to 54 years . . . . . . . 55 to 59 years . . . . . . . 60 to 64 years . . . . . . . 65 to 69 years . . . . . . . 70 to 74 years . . . . . . . 75 to 79 years . . . . . . . 80 to 84 years . . . . . . . 85 to 89 years . . . . . . . 90 to 94 years . . . . . . . 95 to 99 years . . . . . . . 100 years and over . . . 19,175,798 9,810,733 9,365,065 20,201,362 10,319,427 9,881,935 5 . 3 5 . 2 5 . 5 20,549,505 10,523,277 10,026,228 20,348,657 10,389,638 9,959,019 –1 . 0 –1 . 3 –0 . 7 20,528,072 10,520,197 10,007,875 20,677,194 10,579,862 10,097,332 0 . 7 0 . 6 0 . 9 20,219,890 10,391,004 9,828,886 22,040,343 11,303,666 10,736,677 9 . 0 8 . 8 9 . 2 18,964,001 9,687,814 9,276,187 21,585,999 11,014,176 10,571,823 13 . 8 13 . 7 14 . 0 19,381,336 9,798,760 9,582,576 21,101,849 10,635,591 10,466,258 8 . 9 8 . 5 9 . 2 20,510,388 10,321,769 10,188,619 19,962,099 9,996,500 9,965,599 –2 . 7 –3 . 2 –2 . 2 22,706,664 11,318,696 11,387,968 20,179,642 10,042,022 10,137,620 –11 . 1 –11 . 3 –11 . 0 22,441,863 11,129,102 11,312,761 20,890,964 10,393,977 10,496,987 –6 . 9 –6 . 6 –7 . 2 20,092,404 9,889,506 10,202,898 22,708,591 11,209,085 11,499,506 13 . 0 13 . 3 12 . 7 17,585,548 8,607,724 8,977,824 22,298,125 10,933,274 11,364,851 26 . 8 27 . 0 26 . 6 13,469,237 6,508,729 6,960,508 19,664,805 9,523,648 10,141,157 46 . 0 46 . 3 45 . 7 10,805,447 5,136,627 5,668,820 16,817,924 8,077,500 8,740,424 55 . 6 57 . 3 54 . 2 9,533,545 4,400,362 5,133,183 12,435,263 5,852,547 6,582,716 30 . 4 33 . 0 28 . 2 8,857,441 3,902,912 4,954,529 9,278,166 4,243,972 5,034,194 4 . 7 8 . 7 1 . 6 7,415,813 3,044,456 4,371,357 7,317,795 3,182,388 4,135,407 –1 . 3 4 . 5 –5 . 4 4,945,367 1,834,897 3,110,470 5,743,327 2,294,374 3,448,953 16 . 1 25 . 0 10 . 9 2,789,818 876,501 1,913,317 3,620,459 1,273,867 2,346,592 29 . 8 45 . 3 22 . 6 1,112,531 282,325 830,206 1,448,366 424,387 1,023,979 30 . 2 50 . 3 23 . 3

286,784 58,115 228,669 371,244 82,263 288,981 29 . 5 41 . 6 26 . 4

50,454 10,057 40,397 53,364 9,162 44,202 5 . 8 –8 . 9 9 . 4 Median age . . . . . . . . . 35 . 3 34 . 0 36 . 5 37 . 2 35 . 8 38 . 5 (X) (X) (X) (X) Not applicable Sources: U . S . Census Bureau, Census 2000 Summary File 1 and 2010 Census Summary File 1.U.S. Census Bureau 

### 5 half of the population is younger. The median age is often used to describe the “age” of a popula tion. In 2010, the median age increased to a new high of 37.2 years, from 35.3 years in 2000, with the proportion of the popula tion at the older ages increasing similarly (Figure 4). This indicates that the U.S. population is aging. Globally, the median age of the United States is higher than coun tries that are less developed, but younger than most more-developed countries. 3 

### The 1.9 year increase 3 More-developed regions include all regions of Europe, plus Northern America,Australia/New Zealand, and Japan. Lessdeveloped regions include all regions of Africa, Asia (excluding Japan), Latin America, and the Caribbean, plus Melanesia, Micronesia, and Polynesia. For more information, see Population Division of the Department of Economic and Social Affairs of the United Nations Secretariat, **World Population Prospects: The 2008 Revision**  , < http://esa.un.org/unpp >. 

### between 2000 and 2010 was more modest than the 2.4 year increase in median age between 1990 and 2000. The aging of the Baby Boom population into older age groups is contributing to the increase in median age. In the United States, other contributors include stable birth rates and improving mortality. 

### DIFFERENCES IN AGE AND SEX BY GEOGRAPHY A major strength of census data is its detail available at low levels of geography that can highlight variation in age and sex across the United States. This section com pares basic age and sex distribu tions and selected measures among the geographies within regions, states, and counties as well as places with 100,000 or more population. The Northeast had a higher percentage at the older ages, while the West had a higher percentage at the younger ages. In the four census regions, the region with the oldest median age was the Northeast (39.2), fol lowed by the Midwest (37.7), the South (37.0), and the West (35.6). 4 

### Table 3 shows the variation in the distribution of population across

4 The Northeast region includes Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, and Vermont. The Midwest includes Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, and Wisconsin. The South includes Alabama, Arkansas, Delaware, the District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia. The West includes Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, and Wyoming. 

### Figur e 3. 

### Sex Ratio by Age: 2000 and 2010

Note: Sex ratio is calculated as the number of males per 100 females. Sour ces: U.S. Census Bur eau, **Census 2000 Summary File 1**  and **2010 Census Summary File 1**  . (Fo r in for ma tion on conf iden tiality pro tect io n, non sampling er ror , a nd def in ition s, see **www. cen**  **sus.g ov/**  **pro d**  **/ce n2**  **010 /doc/sf1.**  **pdf)**

25.6 28.1 2010 Census 2000 Census

0 20 40 60 80 100 120

100+ 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 Age Ratio

### 6 U.S. Census Bureau 

### four age groups (under 18, 18 to 44, 45 to 64, and 65 and over). Comparing the percentages by age group shows that the West con tains the largest percentages in the age groups under 18 and 18 to 44 (24.9 percent and 37.8 percent, respectively), while the Northeast contains the largest percentages in the age groups 45 to 64 and 65 and over (27.7 percent and 14.1 percent, respectively). The differ ences in distribution of the popula tion across age groups accounts for the differences in median age across the regions. All four regions had a sex ratio of less than 100, indicating more females than males. The sex ratio also varies across regions. The Northeast has the low est sex ratio (94.5 males per 100 females), followed by the South (96.1), the Midwest (96.8), and the West (99.3). All four regions had more females than males in their populations. Maine and Vermont surpassed West Virginia and Florida as the states with the highest median age. More variation in these distribu tions and measures can be seen when looking at state-level com parisons. As expected from the regional data, the states with the highest median ages are located largely in the Northeast, with the exception of West Virginia and Florida (Table 3 and Figure 5). In both 1990 and 2000, West Virginia and Florida had the highest median age of all states. This trend shifted in 2010 due to increases in median age between 2000 and 2010 for the states of Maine, Vermont, and New Hampshire. These three states had the largest increases in median age between 2000 and 2010, with an increase of 3.8 years in Vermont, 4.0 years in New Hampshire, and 4.1 years in Maine. Maine and Vermont surpassed West Virginia and Florida as the states with the highest median age. There were seven states with a median age over 40 years. The five states with the highest median age in 2010 were Maine (42.7), Vermont (41.5), West Virginia (41.3), New Hampshire (41.1), and Florida (40.7). In all, there were seven states, the previ ous five plus Connecticut and Pennsylvania, with a median age of 40 or higher. This was a shift from earlier decades, when all states had a median age below 40. Despite these shifts in median age, however, Florida and West Virginia remained the states with the high est percentage of the population age 65 and over, 17.3 percent and 16.0 percent, respectively. Utah remained the state with the lowest median age. In contrast, the states with the lowest median age (excluding the District of Columbia) remained the same as they were in 2000: Utah (29.2), Texas (33.6), Alaska (33.8), Figur e 4. 

### Age Distribution and Median Age: 1960 to 2010

Sour ces: U.S. Census Bur eau, **2010 Census Summary File 1**  , **Census 2000 Summary File 1**  , **1990 Census Summary File 2C** , **1980 Census Summary File 2C** , **1970 Census of Population,** V ol. 1, **Characteristics of the Population,** Chapter B, T able 50, and **1960 Census of Population,** V ol. 1, **Characteristics of the Population,** Chapter C, T able 156. Under 18 **37.2 35.3**  **32.9 30.0**  **28.1 29.5**  18–44 45–64 65+ **Median age**

1960 1970 1980 1990 2000 2010 (In per cent. Fo r in for ma tion on conf iden tialit y pr ot ec ti on , non sampling er ro r, a nd def in ition s, see **www .cen**  **sus.g ov/**  **pro d/ce**  **n2 010**  **/doc/sf1 .p**  **df)**

24.0 36.5 26.4 13.0 25.7 39.9 22.0 12.4 25.6 43.2 18.6 12.6 28.1 40.9 19.6 11.3 34.3 35.3 20.6 9.8 35.9 34.8 20.3 9. 0U.S. Census Bureau 

### 7 Table 3. 

### Population by Sex and Selected Age Groups for the United States, Regions, States, and Puerto Rico: 2010 (For information on confidentiality protection, nonsampling error, and definitions, see **www.census.gov/prod/cen2010/doc/sf1.pdf** ) Area Both sexes Male Female Sex ratio Under 18 years 18 to 44 years 45 to 64 years 65 years and over Median age Number Per cent Number Per cent Number Per cent Number Per cent **United States . . .**  **308,745,538 151,781,326**  **156,964,212 96**  **. 7**  **74,181,467 24**  **. 0**  **112,806,642 36**  **. 5**  **81,489,445 26**  **. 4**  **40,267,984 13**  **. 0**  **37 .**  **2 REGION**  Northeast . . . . . . . . 55,317,240 26,869,408 28,447,832 94 . 5 12,333,192 22 . 3 19,873,499 35 . 9 15,305,716 27 . 7 7,804,833 14 . 1 39 . 2 Midwest . . . . . . . . . 66,927,001 32,927,560 33,999,441 96 . 8 16,128,108 24 . 1 23,722,312 35 . 4 18,054,247 27 . 0 9,022,334 13 . 5 37 . 7 South . . . . . . . . . . . 114,555,744 56,134,681 58,421,063 96 . 1 27,788,757 24 . 3 42,002,579 36 . 7 29,870,423 26 . 1 14,893,985 13 . 0 37 . 0 West . . . . . . . . . . . . 71,945,553 35,849,677 36,095,876 99 . 3 17,931,410 24 . 9 27,208,252 37 . 8 18,259,059 25 . 4 8,546,832 11 . 9 35 . 6 **STATE** Alabama . . . . . . . . . 4,779,736 2,320,188 2,459,548 94 . 3 1,132,459 23 . 7 1,707,598 35 . 7 1,281,887 26 . 8 657,792 13 . 8 37 . 9 Alaska . . . . . . . . . . . 710,231 369,628 340,603 108 . 5 187,378 26 . 4 270,980 38 . 2 196,935 27 . 7 54,938 7 . 7 33 . 8 Arizona . . . . . . . . . . 6,392,017 3,175,823 3,216,194 98 . 7 1,629,014 25 . 5 2,312,398 36 . 2 1,568,774 24 . 5 881,831 13 . 8 35 . 9 Arkansas . . . . . . . . 2,915,918 1,431,637 1,484,281 96 . 5 711,475 24 . 4 1,026,205 35 . 2 758,257 26 . 0 419,981 14 . 4 37 . 4 California . . . . . . . . 37,253,956 18,517,830 18,736,126 98 . 8 9,295,040 25 . 0 14,423,538 38 . 7 9,288,864 24 . 9 4,246,514 11 . 4 35 . 2 Colorado . . . . . . . . . 5,029,196 2,520,662 2,508,534 100 . 5 1,225,609 24 . 4 1,913,620 38 . 1 1,340,342 26 . 7 549,625 10 . 9 36 . 1 Connecticut . . . . . . 3,574,097 1,739,614 1,834,483 94 . 8 817,015 22 . 9 1,231,474 34 . 5 1,019,049 28 . 5 506,559 14 . 2 40 . 0 Delaware . . . . . . . . 897,934 434,939 462,995 93 . 9 205,765 22 . 9 318,409 35 . 5 244,483 27 . 2 129,277 14 . 4 38 . 8 District of Columbia . 601,723 284,222 317,501 89 . 5 100,815 16 . 8 292,419 48 . 6 139,680 23 . 2 68,809 11 . 4 33 . 8 Florida . . . . . . . . . . 18,801,310 9,189,355 9,611,955 95 . 6 4,002,091 21 . 3 6,460,456 34 . 4 5,079,161 27 . 0 3,259,602 17 . 3 40 . 7 Georgia . . . . . . . . . . 9,687,653 4,729,171 4,958,482 95 . 4 2,491,552 25 . 7 3,703,257 38 . 2 2,460,809 25 . 4 1,032,035 10 . 7 35 . 3 Hawaii . . . . . . . . . . . 1,360,301 681,243 679,058 100 . 3 303,818 22 . 3 492,018 36 . 2 369,327 27 . 2 195,138 14 . 3 38 . 6 Idaho . . . . . . . . . . . 1,567,582 785,324 782,258 100 . 4 429,072 27 . 4 554,992 35 . 4 388,850 24 . 8 194,668 12 . 4 34 . 6 Illinois . . . . . . . . . . . 12,830,632 6,292,276 6,538,356 96 . 2 3,129,179 24 . 4 4,748,154 37 . 0 3,344,086 26 . 1 1,609,213 12 . 5 36 . 6 Indiana . . . . . . . . . . 6,483,802 3,189,737 3,294,065 96 . 8 1,608,298 24 . 8 2,318,485 35 . 8 1,715,911 26 . 5 841,108 13 . 0 37 . 0 Iowa . . . . . . . . . . . . 3,046,355 1,508,319 1,538,036 98 . 1 727,993 23 . 9 1,052,998 34 . 6 812,476 26 . 7 452,888 14 . 9 38 . 1 Kansas . . . . . . . . . . 2,853,118 1,415,408 1,437,710 98 . 4 726,939 25 . 5 1,012,552 35 . 5 737,511 25 . 8 376,116 13 . 2 36 . 0 Kentucky . . . . . . . . . 4,339,367 2,134,952 2,204,415 96 . 8 1,023,371 23 . 6 1,555,679 35 . 9 1,182,090 27 . 2 578,227 13 . 3 38 . 1 Louisiana . . . . . . . . . 4,533,372 2,219,292 2,314,080 95 . 9 1,118,015 24 . 7 1,667,563 36 . 8 1,189,937 26 . 2 557,857 12 . 3 35 . 8 Maine . . . . . . . . . . . 1,328,361 650,056 678,305 95 . 8 274,533 20 . 7 432,072 32 . 5 410,676 30 . 9 211,080 15 . 9 42 . 7 Maryland . . . . . . . . . 5,773,552 2,791,762 2,981,790 93 . 6 1,352,964 23 . 4 2,114,974 36 . 6 1,597,972 27 . 7 707,642 12 . 3 38 . 0 Massachusetts . . . . 6,547,629 3,166,628 3,381,001 93 . 7 1,418,923 21 . 7 2,410,178 36 . 8 1,815,804 27 . 7 902,724 13 . 8 39 . 1 Michigan . . . . . . . . . 9,883,640 4,848,114 5,035,526 96 . 3 2,344,068 23 . 7 3,416,012 34 . 6 2,762,030 27 . 9 1,361,530 13 . 8 38 . 9 Minnesota . . . . . . . . 5,303,925 2,632,132 2,671,793 98 . 5 1,284,063 24 . 2 1,899,479 35 . 8 1,437,262 27 . 1 683,121 12 . 9 37 . 4 Mississippi . . . . . . . 2,967,297 1,441,240 1,526,057 94 . 4 755,555 25 . 5 1,067,034 36 . 0 764,301 25 . 8 380,407 12 . 8 36 . 0 Missouri . . . . . . . . . 5,988,927 2,933,477 3,055,450 96 . 0 1,425,436 23 . 8 2,113,347 35 . 3 1,611,850 26 . 9 838,294 14 . 0 37 . 9 Montana . . . . . . . . . 989,415 496,667 492,748 100 . 8 223,563 22 . 6 330,420 33 . 4 288,690 29 . 2 146,742 14 . 8 39 . 8 Nebraska . . . . . . . . . 1,826,341 906,296 920,045 98 . 5 459,221 25 . 1 648,541 35 . 5 471,902 25 . 8 246,677 13 . 5 36 . 2 Nevada . . . . . . . . . . 2,700,551 1,363,616 1,336,935 102 . 0 665,008 24 . 6 1,019,158 37 . 7 692,026 25 . 6 324,359 12 . 0 36 . 3 New Hampshire . . . . 1,316,470 649,394 667,076 97 . 3 287,234 21 . 8 446,764 33 . 9 404,204 30 . 7 178,268 13 . 5 41 . 1 New Jersey . . . . . . . 8,791,894 4,279,600 4,512,294 94 . 8 2,065,214 23 . 5 3,115,326 35 . 4 2,425,361 27 . 6 1,185,993 13 . 5 39 . 0 New Mexico . . . . . . 2,059,179 1,017,421 1,041,758 97 . 7 518,672 25 . 2 719,307 34 . 9 548,945 26 . 7 272,255 13 . 2 36 . 7 New York . . . . . . . . . 19,378,102 9,377,147 10,000,955 93 . 8 4,324,929 22 . 3 7,252,871 37 . 4 5,182,359 26 . 7 2,617,943 13 . 5 38 . 0 North Carolina . . . . 9,535,483 4,645,492 4,889,991 95 . 0 2,281,635 23 . 9 3,512,362 36 . 8 2,507,407 26 . 3 1,234,079 12 . 9 37 . 4 North Dakota . . . . . 672,591 339,864 332,727 102 . 1 149,871 22 . 3 246,767 36 . 7 178,476 26 . 5 97,477 14 . 5 37 . 0 Ohio . . . . . . . . . . . . . 11,536,504 5,632,156 5,904,348 95 . 4 2,730,751 23 . 7 3,989,281 34 . 6 3,194,457 27 . 7 1,622,015 14 . 1 38 . 8 Oklahoma . . . . . . . . 3,751,351 1,856,977 1,894,374 98 . 0 929,666 24 . 8 1,348,878 36 . 0 966,093 25 . 8 506,714 13 . 5 36 . 2 Oregon . . . . . . . . . . 3,831,074 1,896,002 1,935,072 98 . 0 866,453 22 . 6 1,382,447 36 . 1 1,048,641 27 . 4 533,533 13 . 9 38 . 4 Pennsylvania . . . . . . 12,702,379 6,190,363 6,512,016 95 . 1 2,792,155 22 . 0 4,388,169 34 . 5 3,562,748 28 . 0 1,959,307 15 . 4 40 . 1 Rhode Island . . . . . . 1,052,567 508,400 544,167 93 . 4 223,956 21 . 3 383,791 36 . 5 292,939 27 . 8 151,881 14 . 4 39 . 4 South Carolina . . . . 4,625,364 2,250,101 2,375,263 94 . 7 1,080,474 23 . 4 1,669,793 36 . 1 1,243,223 26 . 9 631,874 13 . 7 37 . 9 South Dakota . . . . . 814,180 407,381 406,799 100 . 1 202,797 24 . 9 280,080 34 . 4 214,722 26 . 4 116,581 14 . 3 36 . 9 Tennessee . . . . . . . 6,346,105 3,093,504 3,252,601 95 . 1 1,496,001 23 . 6 2,284,491 36 . 0 1,712,151 27 . 0 853,462 13 . 4 38 . 0 Texas . . . . . . . . . . . 25,145,561 12,472,280 12,673,281 98 . 4 6,865,824 27 . 3 9,644,824 38 . 4 6,033,027 24 . 0 2,601,886 10 . 3 33 . 6 Utah . . . . . . . . . . . . 2,763,885 1,388,317 1,375,568 100 . 9 871,027 31 . 5 1,096,191 39 . 7 547,205 19 . 8 249,462 9 . 0 29 . 2 Vermont . . . . . . . . . 625,741 308,206 317,535 97 . 1 129,233 20 . 7 212,854 34 . 0 192,576 30 . 8 91,078 14 . 6 41 . 5 Virginia . . . . . . . . . . 8,001,024 3,925,983 4,075,041 96 . 3 1,853,677 23 . 2 3,001,446 37 . 5 2,168,964 27 . 1 976,937 12 . 2 37 . 5 Washington . . . . . . . . 6,724,540 3,349,707 3,374,833 99 . 3 1,581,354 23 . 5 2,492,139 37 . 1 1,823,370 27 . 1 827,677 12 . 3 37 . 3 West Virginia . . . . . . . 1,852,994 913,586 939,408 97 . 3 387,418 20 . 9 627,191 33 . 8 540,981 29 . 2 297,404 16 . 0 41 . 3 Wisconsin . . . . . . . . 5,686,986 2,822,400 2,864,586 98 . 5 1,339,492 23 . 6 1,996,616 35 . 1 1,573,564 27 . 7 777,314 13 . 7 38 . 5 Wyoming . . . . . . . . . 563,626 287,437 276,189 104 . 1 135,402 24 . 0 201,044 35 . 7 157,090 27 . 9 70,090 12 . 4 36 . 8 **Puerto Rico . . . . . .**  **3,725,789 1,785,171**  **1,940,618 92**  **. 0**  **903,295 24**  **. 2**  **1,351,005 36**  **. 3**  **929,491 24**  **. 9**  **541,998 14**  **. 5**  **36 .**  **9** Note: Sex ratio is calculated as the number of males per 100 females . Source: U . S . Census Bureau, 2010 Census Summary File 1 .

### 8 U.S. Census Bureau 

### and Idaho (34.6). Among the states, Utah had the highest percentage of its population under age 18 (31.5 percent), which contributed to its low median age. Utah remained the only state with a median age under 30. All states experienced an increase in median age when compared with 2000—a further indication of population aging. The District of Columbia experienced a decrease in median age, going from 34.6 years to 33.8 years. In the District of Columbia, almost half (48.6 percent) of the 2010 Census population was ages 18 to 44. Sex ratios were higher in Western states and lower in Northeastern states. Table 3 contains the sex ratio for each state. There were ten states with more males than females in the population, indicated by a sex ratio greater than 100. These states were concentrated in the West and Midwest: Alaska (108.5 males per 100 females), Wyoming (104.1), North Dakota (102.1), Nevada (102.0), Utah (100.9), Montana (100.8), Colorado (100.5), Idaho (100.4), Hawaii (100.3), and South Dakota (100.1). In contrast, the five states with the lowest sex ratios (excluding the District of Columbia from the ranking) were concentrated in the Northeast and South: Rhode Island (93.4 males per 100 females), Maryland (93.6), Massachusetts (93.7), New York (93.8), and Delaware (93.9). The District of Columbia had the lowest sex ratio, at 89.5 males per 100 females. Counties with lower sex ratios were found in Northeastern states, while counties with higher sex ratios were found in Western states. Data for age and sex were also evaluated for every county in the MT AK

NM OR MN

KS SD ND

MO WA

FL IL IN WI NY PA MI OH IA ME MA CT

AZ

HI NV

TX CO CA WY UT ID

NE

OK GA AR AL NC MS LA TN KY VA

SC WV RI DE MD DC NJ 

### Figur e 5. 

### Median Age by State: 2010

VT NH

U.S. median: 37.2 Median age 40.0 or mor e 37.5 to 39.9 35.0 to 37.4 Less than 35.0

PR (F or in fo rm a tion on conf iden tiality pro tect io n, non sampling er ror , a nd def in ition s, se e **www .cen**  **sus.g ov/**  **pro d/ce**  **n2 010**  **/doc/sf1. pdf)** 

Sour ce: U.S. Census Bu re au, **2010 Census Summary File 1**  .U.S. Census Bureau 

### 9 United States. 5 

### These sex ratios are illustrated in Figure 6, which provides a map of sex ratios by county. From this map, it is evi dent that counties in Northeastern and Southern states tend to have lower sex ratios, while counties in Western and Midwestern states tend to have higher sex ratios. In 2010, Alaska was the only state where males outnumbered females in every county. In 2000, Alaska, Hawaii, and Nevada had a greater number of males than females in every county. In 2010, three states had a sex ratio below 100 in every county: Delaware, Maine, and Rhode Island. Both Delaware and Rhode Island had sex ratios that were below the national level (96.7) in every county. Compared to 2000, there were fewer counties in 2010 where the female population outnumbered the male population. Of the 3,143 total counties in the United States, 1,096 of these (34.9 percent) had a sex ratio that was less than the national sex ratio of 96.7. In all, there were a total of 2,089 counties (66.5 percent) with a sex ratio below 100, indi cating that the female population in the county outnumbered the male population. This is a decrease from what was seen in 2000, when

5 The primary legal divisions of most states are termed “counties.” In Louisiana, these divisions are known as parishes. In Alaska, which has no counties, the statisti cally equivalent entities are census areas, city and boroughs (as in Juneau City and Borough), a municipality (Anchorage), and organized boroughs. Census areas are delineated cooperatively for data presenta tion purposes by the state of Alaska and the U.S. Census Bureau. In four states (Maryland, Missouri, Nevada, and Virginia), there are one or more incorporated places that are inde pendent of any county organization and thus constitute primary divisions of their states; these incorporated places are known as “inde pendent cities” and are treated as equivalent to counties for data presentation purposes. The District of Columbia has no primary divisions, and the entire area is considered equivalent to a county and a state for data presentation purposes. 

### 73 percent of counties had a sex ratio less than 100. The county with the highest sex ratio was Crowley County, Colorado, with a sex ratio of 258.6, indicating that there were more than twice as many men as women in the county. This high sex ratio results from the presence of a state prison in Crowley County. The lowest sex ratio was found in Pulaski County, Georgia, with a sex ratio of 76.1. This low sex ratio is partly due to the presence of a state prison for women in Pulaski County. The total population of each of these counties, however, was less than 12,500 people. Among counties with at least 100,000 people, there were three counties with a sex ratio greater than 110: Kings County, California (129.6), Onslow County, North Carolina (115.7), and Pinal County, Arizona (110.4). In both Kings County and Pinal County, the high sex ratios are due to the presence of multiple correctional facilities with majority male populations, while Onslow County owes its high sex ratio to the presence of a large Marine Corps base that houses a mostly male population. The lowest sex ratios among counties with at least 100,000 people were found in Hampshire County, Massachusetts (88.0), Bronx County, New York (88.3), and New York County, New York (88.3). In Hampshire County, the low sex ratio is influenced by the presence of several colleges, two of which are women’s colleges. County-level median ages followed patterns seen at the state level. There was also variation at the county level in the median age. Figure 7 provides a map of median age by county for all counties in the United States. While median age varied significantly among counties, patterns emerge that are consis tent with findings reported earlier. For example, counties in Florida, New England, and the Appalachian Mountain area tend to have higher median ages, along with a band of counties in the Great Plains and Pacific Northwest. Counties with lower median ages are found clustered along the United States– Mexico border and within the states of Utah and Alaska. The number of counties with a median age over 40 grew, while those with a median age less than 30 declined between 2000 and 2010. Of the country’s 3,143 counties, there were 1,683 counties with a median age over 40. This is an increase of more than double from Census 2000, where 734 counties were found to have a median age over 40. In contrast, there were only 93 counties with a median age below 30, compared with 131 counties in 2000. The county with the highest median age was Sumter County, Florida (62.7), a county with a population of just under 93,500, which is home to a large, age-restricted retirement commu nity. The lowest median age was found in the Wade Hampton Census Area, Alaska (21.9), a county with a population of less than 7,500. Among counties with a population of at least 100,000, the counties with the highest median ages were found in Florida. Examining counties with a popula tion of at least 100,000 shows that three counties, all in Florida, had a median age over 50: Charlotte (55.9), Citrus (54.0), and Sarasota (52.5). These were also the coun ties with the highest median ages in 2000. Counties with a low median age were consistent between 2000 and 2010 as well. The lowest median ages were

### 10 U.S. Census Bureau0 100Miles0 200Miles0 100Miles0 50 MilesFigure 6.Sex Ratio by County: 2010(For informationonconfidentialityprotection,nonsamplingerror, anddefinitions, see**www .cen** **sus.g ov** **/p ro** **d/ce n2** **010 /doc/sf1.** **pdf)**Note: Sex ratio is calculated as the numberof males per 100 females.Source: U.S. Census Bureau,**2010 Census Summary File** **1**.Sex ratioU.S. sex ratio: 96.7105.0 or more100.0 to 104.995.0 to 99.9Less than 95.0U.S. Census Bureau 

### 110 100Miles0 200Miles0 100Miles0 50 MilesMedian age50.0 or more45.0 to 49.940.0 to 44.935.0 to 39.930.0 to 34.9Less than 30.0U.S. median: 37.2Figure 7.Median Age by County: 2010(For informationonconfidentialityprotection,nonsamplingerror, anddefinitions, see**www .cen** **sus.g ov/** **pro d/ce** **n2 010** **/doc/sf1. pdf)** Source: U.S. Census Bureau,**2010 Census Summary File** **1**.

### 12 U.S. Census Bureau 

### found in Brazos County, Texas (24.5), Utah County, Utah (24.6), Cache County, Utah (25.5), Onslow County, North Carolina (25.7), and Clarke County, Georgia (25.9). Three of these counties contain large universities, which drive the low median age in each county. Brazos County, Texas, is home to Texas A&M University; Utah County, Utah, contains Brigham Young University; and the University of Georgia is located in Clarke County, Georgia. As mentioned previously, Onslow County, North Carolina, is home to a large Marine Corps base with a primarily young, male population. The presence of this base contributes to the low median age and high sex ratio in the county. With the exception of Cache County, Utah, which was below 100,000 in population in 2000, all of these counties were also in the lowest five for median age in 2000 as well. Among places of 100,000 or more population, the places with the highest and the lowest sex ratio were both in Florida. Table 4 provides a list of the ten places (among places with a population of 100,000 or more) with the highest and lowest sex ratio in 2010. 6 

### The highest sex ratio was found in Fort Lauderdale, Florida (111.8), followed by Tempe, Arizona (108.6), and Wichita Falls, Texas (107.5). Of the top ten places with the highest sex ratio, six are in the West, with the remaining four in Southern states. As mentioned pre viously, both Utah and Washington were among the states with the highest sex ratios, and both states contained a place with a sex ratio among the top ten places: Salt Lake City, Utah, with a sex ratio of 105.3 6 The 2010 Census showed 282 places in the United States with 100,000 or more popu lation. They included 273 incorporated places (including 5 consolidated cities) and 9 census designated places (CDPs) that were not legally incorporated. 

### and Everett, Washington, with a sex ratio of 103.5. Interestingly, the place with the highest sex ratio and the place with the lowest sex ratio were found in Florida. The highest sex ratio was found in Fort Lauderdale, Florida (111.8), while the lowest sex ratio was found in Pembroke Pines, Florida (85.9). All ten of the places with the lowest sex ratios were found in Southern states. The list of the lowest sex ratios included several places from the same states, with three places each from Alabama and North Carolina, and two from Florida. Among places with a population of 100,000 or more, five of the ten places with the highest median ages were located in Florida. The ten places with a population of 100,000 or more with the high est median ages were located in the South and West regions (Table 5). Scottsdale, Arizona, had the highest median age at 45.4 years— a value 8 years higher than the national median age. Of the remain ing places with the highest median age, five were found in Florida and two were in California. Florida also had two places that were included on the list of places with the lowest median age: Gainesville, Florida (24.9), and Tallahassee, Florida (26.1). The place with the lowest median age was found in Provo, Utah (23.3), which is located in the state with the lowest median age overall. All three of these places were home to prominent universities, which directly contributed to their low median age. Provo, Utah, located in Utah County, as mentioned ear lier, is the home of Brigham Young University. Gainesville, Florida, is the home of the University of Florida, while Tallahassee, Florida, is home Table 4. 

### Ten Places With the Highest and Lowest Sex Ratio: 2010 (For information on confidentiality protection, nonsampling error, and definitions, see **www.census.gov/prod/cen2010/doc/sf1.pdf** ) Place 1 Both sexes Male Female Sex ratio **HIGHEST SEX RATIO** Fort Lauderdale, FL . . . . . . . . . 165,521 87,387 78,134 111 . 8 Tempe, AZ . . . . . . . . . . . . . . . . 161,719 84,200 77,519 108 . 6 Wichita Falls, TX . . . . . . . . . . . 104,553 54,172 50,381 107 . 5 Norfolk, VA . . . . . . . . . . . . . . . . 242,803 125,797 117,006 107 . 5 Paradise CDP, NV . . . . . . . . . . 223,167 115,508 107,659 107 . 3 Columbia, SC . . . . . . . . . . . . . 129,272 66,532 62,740 106 . 0 Salt Lake City, UT . . . . . . . . . . 186,440 95,627 90,813 105 . 3 Santa Ana, CA . . . . . . . . . . . . . 324,528 165,752 158,776 104 . 4 Costa Mesa, CA . . . . . . . . . . . 109,960 55,968 53,992 103 . 7 Everett, WA . . . . . . . . . . . . . . . 103,019 52,392 50,627 103 . 5 **LOWEST SEX RATIO** Pembroke Pines, FL . . . . . . . . 154,750 71,515 83,235 85 . 9 Jackson, MS . . . . . . . . . . . . . . 173,514 80,615 92,899 86 . 8 Miami Gardens, FL . . . . . . . . . 107,167 50,121 57,046 87 . 9 Birmingham, AL . . . . . . . . . . . . 212,237 99,337 112,900 88 . 0 Shreveport, LA . . . . . . . . . . . . . 199,311 93,354 105,957 88 . 1 High Point, NC . . . . . . . . . . . . . 104,371 49,002 55,369 88 . 5 Winston-Salem, NC . . . . . . . . . 229,617 107,878 121,739 88 . 6 Montgomery, AL . . . . . . . . . . . 205,764 96,687 109,077 88 . 6 Greensboro, NC . . . . . . . . . . . . . 269,666 126,793 142,873 88 . 7 Mobile, AL . . . . . . . . . . . . . . . . 195,111 91,783 103,328 88 . 8 1 Places of 100,000 or more total population . The 2010 Census showed 282 places in the United States with 100,000 or more population . They included 273 incorporated places (including 5 consolidated cities) and 9 census designated places (CDPs) that were not legally incorporated . Source: U . S . Census Bureau, 2010 Census Summary File 1.U.S. Census Bureau 

### 13 to both Florida State University and Florida A&M University. In all, nine of the ten places on the list of the places with the lowest median age contain large universities, with the remaining place, Killeen, Texas, home to a large military base. Three places in Texas are on the list of the ten lowest median ages. 

### ADDITIONAL FINDINGS ON AGE AND SEX At what age were there almost twice as many women as men? In the 2010 Census, there were approximately twice as many women as men at age 89 (361,309 compared with 176,689, respec tively). This point occurs about 4 years older than it did in 2000, and 6 years older than it did in 1990. This increase is further evidence of the narrowing gap in mortality between men and women occurring at the older ages. What are age heaping and digit preference? The tendency for respondents to report certain ages at the expense of other ages is called age heap ing. This is also referred to as digit preference, which is the preference for certain ages, such as those end ing in “0” or “5.” Age preference can also include preference for a par ticular age, like 29, 65, 85 or 100. This phenomenon varies across cultures and is impacted by data collection methods. The Census Bureau strives to reduce age heap ing by collecting both age and date of birth information. Overall, age heaping did not appear to be a concern at the national level in Census 2000. 7 

### Early evaluations of the 2010 Census data show similar results.

7 For more information, see Kirsten West, “Did Proxy Respondents Cause Age Heaping in Census 2000.” Paper presented at the Annual Meeting of the American Statistical Association, August 7–11, 2005. 

### What drove the overall decline in the age dependency ratio? The age dependency ratio provides a very rough approximation of economic dependency in a popula tion by dividing the dependent-age population (children and older adults) by the working-age popula tion. It is often derived as the num ber of people in the “dependent” age categories (under age 18 and 65 and over) per 100 working-age people (18 to 64). This ratio can beseparated into two parts, the oldage dependency ratio (65 and over divided by the working-age popu lation) and the child dependency ratio (under-18 population divided by the working-age population). At the national level, the total age dependency ratio declined from 61.6 in 2000 to 58.9 in 2010, indicating that there were 2.7 fewer “dependent-age” people for every 100 working-age people. However, this overall decline masks the differing trends occurring in the younger and older population. When evaluating the two depen dency ratios separately, the child dependency ratio declined by 3.3 (from 41.5 in 2000 to 38.2 in 2010) while the old-age dependency ratio increased slightly by 0.6 (20.1 in 2000 to 20.7 in 2010). How does the dependency ratio differ by state? Dependency ratios also varied from state to state, mirroring trends in median age by state that were discussed earlier. Figure 8 presents dependency ratios for every state, decomposing the total dependency ratio into its two parts (the old-age dependency ratio and the child dependency ratio). States are ranked according to their total dependency ratios. As is evident in Figure 8, Utah was the state with the highest total dependency ratio, and it also had the highest child dependency ratio. This is not surprising, given Table 5. 

### Ten Places With the Highest and Lowest Median Age: 2010 (For information on confidentiality protection, nonsampling error, and definitions, see **www.census.gov/prod/cen2010/doc/sf1.pdf** ) Place 1 Median age (years) **HIGHEST MEDIAN AGE** Scottsdale, AZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 . 4 Clearwater, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 . 8 Cape Coral, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 . 4 Fort Lauderdale, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 . 2 Hialeah, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 . 2 St . Petersburg, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 . 6 Thousand Oaks, CA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 . 5 Urban Honolulu CDP, HI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 . 3 Torrance, CA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 . 3 Centennial City, CO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 . 1 **LOWEST MEDIAN AGE** Provo, UT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 . 3 Gainesville, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 . 9 Athens-Clarke County unified government, GA . . . . . . . . . . . . . . . . . . 25 . 9 Tallahassee, FL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 . 1 Columbia, MO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 . 8 Killeen, TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 . 1 Denton, TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 . 1 Ann Arbor, MI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 . 8 Laredo, TX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 . 9 Tempe, AZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 . 1 1 Places of 100,000 or more total population . The 2010 Census showed 282 places in the United States with 100,000 or more population . They included 273 incorporated places (including 5 consolidated cities) and 9 census designated places (CDPs) that were not legally incorporated . Source: U . S . Census Bureau, 2010 Census Summary File 1 .

### 14 U.S. Census Bureau 

### Figur e 8. 

### Age Dependency Ratios by State: 2010 (For information on confidentiality pr otection, nonsampling err or , and definitions, see **www .census.gov/prod/cen2010/doc/sf1.pdf**  )

Note: T otal bar length r epr esents the total dependency ratio, which is the number of childr en (ages 0–17) and older adults (age s 65 and over) per 100 people of working age (ages 18–64) in the state. Sour ce: U.S. Census Bur eau, **2010 Census Summary File 1**  . Old-age dependency ratio Child dependency ratio

0 1 0 2 0 3 0 4 0 50 60 70 District of Columbia Alaska V ermont Colorado New Hampshir e Vi r ginia Massachusetts Maryland Rhode Island

W ashington

New Y ork California

Geor gi a Wyoming

Or egon

Maine Nevada Hawaii North Dakota North Car olin a Kentucky Illinois W est Vi rg inia Louisiana New Jersey South Ca ro lina T

ennessee Connecticut United States Minnesota Wisconsin Delawar e Pennsylvania Montana Alabama Michigan T

exas Ohio Indiana Missouri Mississippi Oklahoma New Mexico Florida Nebraska

Kansas

Iowa Arkansas South Dakota Arizona

Idaho Utah

Rati oU.S. Census Bureau 

### 15 that Utah was the state with the lowest median age, as mentioned previously. The lowest child depen dency ratio was found in Vermont, a state that also had a high median age. Excluding the District of Columbia, the state with the lowest total dependency ratio was Alaska. Alaska was also the state with the lowest old-age dependency ratio,while the state with the highest oldage dependency ratio was Florida, again matching trends in median age mentioned previously for these states. The District of Columbia had the lowest dependency ratio overall. 

### ABOUT THE 2010 CENSUS Why was the 2010 Census conducted? The U.S. Constitution mandates that a census be taken in the United States every 10 years. This is required in order to determine the number of seats each state is to receive in the U.S. House of Representatives. Age data are used to determine the voting age popu lation (age 18 and older) for use in the legislative redistricting process. Why did the 2010 Census ask the questions on age and sex? The Census Bureau collects data on age and sex to support a variety of legislative and program require ments. These data are also used to aid in allocating funds from federal programs, in particular to programs targeting specific age groups. For example, age data are used tocalculate the proportion of schoolaged children in each district in order to properly allocate funds for education. How are age and sex data beneficial? All levels of government need information on age and sex to implement and evaluate programs, such as the Equal Employment Opportunity Act, the Civil Rights Act, the Women’s Educational Equity Act, the Older Americans Act, the Juvenile Justice and Delinquency Prevention Act, and the Job Training Partnership Act. Age and sex data are used by the Department of Veterans Affairs, the Department of Education, the Department of Health and Human Services, and the Equal Employment Opportunity Commission, among others, to aid in planning and development of services. Other equally important uses for census age and sex data are in planning adequate schools for the school age population and to determine funding distributions for schools and planning for numerous social services such as highways, hospitals, health services, and services for the older population. Census age data are also an impor tant source of information on popu lation aging, such as measurement of people eligible for Social Security and Medicare benefits. In addition to these public uses of census data, census data can also be used by private organizations. For example, census data can help researchers studying trends related to mortality and population aging or help small business owners in planning where to best locate their businesses to fit the needs of the community. 

### FOR MORE INFORMATION For more information on age and sex in the United States, visit the U.S. Census Bureau’s Internet sites at < www.census.gov/population /www/socdemo/age/ > and < www.census.gov/population /www/socdemo/women.html >. Data on age and sex from the **2010 Census Summary File 1** pro vide information at the state level and below and are available on the Internet at < factfinder2 .census.gov/main.html > and on DVD. Information on confidential ity protection, nonsampling error, and definitions is available on the Census Bureau’s Internet site at < www.census.gov/prod/cen2010 /doc/sf1.pdf >. Information on other population and housing topics is presented in the 2010 Census Briefs series, located on the U.S. Census Bureau’s Web site at < www.census.gov /prod/cen2010/ >. This series presents information about race, Hispanic origin, age, sex, house hold type, housing tenure, and peo ple who reside in group quarters. For more information about the 2010 Census, including data prod ucts, call the Customer Services Center at 1-800-923-8282. You can also visit the Census Bureau’s Question and Answer Center at < ask.census.gov > to submit your questions online. Contents INTRODUCTION 1 SEX AND AGE QUESTIONS 1 AGE AND SEX COMPOSITION 2 The population grew at a faster rate in the older ages than in the younger ages. 2 Faster growth in the male popula tion led to increased sex ratios. 4 Population aging led to an increased median age. 4 DIFFERENCES IN AGE AND SEX BY GEOGRAPHY 5 The Northeast had a higher per centage at the older ages, while the West had a higher percentage at the younger ages. 5 All four regions had a sex ratio of less than 100, indicating more females than males. 6 Maine and Vermont surpassed West Virginia and Florida as the states with the highest median age. 6 There were seven states with a median age over 40 years. 6 Utah remained the state with the lowest median age. 6 Sex ratios were higher in Western states and lower in Northeastern states. 8 Counties with lower sex ratios were found in Northeastern states, while counties with higher sex ratios were found in Western states. 8 Compared to 2000, there were fewer counties in 2010 where the female population outnumbered the male population. 9 County-level median ages followed patterns seen at the state level. 9 The number of counties with a median age over 40 grew, while those with a median age less than 30 declined between 2000 and 2010. 9 Among counties with a population of at least 100,000, the counties with the highest median ages were found in Florida. 9 Among places of 100,000 or more population, the places with the highest and the lowest sex ratio were both in Florida. 12 Among places with a population of 100,000 or more, five of the ten places with the highest median ages were located in Florida. 12 ADDITIONAL FINDINGS ON AGE AND SEX 13 At what age were there almost twice as many women as men? 13 What are age heaping and digit preference? 13 What drove the overall decline in the age dependency ratio? 13 How does the dependency ratio differ by state? 13 ABOUT THE 2010 CENSUS 15 Why was the 2010 Census con ducted? 15 Why did the 2010 Census ask the questions on age and sex? 15 How are age and sex data benefi cial? 15 FOR MORE INFORMATION 15

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